Knuckles' theme is the theme of Knuckles the Echidna in Sonic the Hedgehog 3 and Sonic & Knuckles. The music plays whenever Knuckles appears in Sonic's or Tails' story to ruin their plans or to stop Dr. Ivo "Eggman" Robotnik. The percussion line was also used in the miniboss fight theme. The well-known superstar Michael Jackson may have had some involvement in the Sonic 3 soundtrack. Many have noticed that this theme sounds similar to "In the Closet", "Ghosts", and "Blood on the Dance Floor", all three being by Jackson. In Sonic and Knuckles, the hip-hop beat was replaced with a much more tribal sounding theme, probably as a result of licensing issues. This version also plays in both the Genesis and PC versions of Sonic 3 and Knuckles.